Prior displays for tuning apparatuses include displays such as disclosed in Japanese Laid-Open Patent Application Publication (Kokai) Number 2002-323893. In FIG. 3 and FIG. 4 of that publication, a tuning guide is configured with a plurality of indicators that are arranged in a row. The higher the pitch that the input musical tone signal is relative to a standard pitch, the further to the right of the center is the indicator that lights. Similarly, the lower the pitch that the input musical tone signal is relative to the standard pitch, the further to the left from the center is the indicator that lights.
With that apparatus, it is possible to carry out a display corresponding to that of a mechanical meter, but without the use of a mechanical meter. However, in an apparatus where LEDs are used as the indicators, if a diffusion material is added to the cover that is attached to each LED in order to diffuse the light, the visibility can become poor in bright locations where the lighting or sunlight strikes the LED. Therefore, LEDs that have a high degree of brightness have be employed as the indicators. On the other hand, in apparatuses in which the LED covers do not use a diffusion material to increase the visibility in bright locations, the light from the LEDs can have the appearance of point light sources, which degrades the appearance of the overall display as a line light source display that simulates a mechanical meter. In addition, in order to achieve a continuous line light source display using LEDs, the distance between adjacent LEDs has been made relatively short. Therefore, if a light isolation member is not arranged between adjacent LEDs, light leakage between adjacent LEDs is likely to occur.